Peter bumped into his old friend Sam whom he hadn't seen for ages.
"So good to see you Sam! It's been years. I've had three children since then. You're very clever; perhaps you can tell me their ages? If you multiply them together, you get 36 and if you add them together the sum will be the number of the house we're standing outside."
"Not enough information," replied Sam.
"Ok here's another clue: my eldest child's just come back from picking flowers."
"I've worked it out," said Sam.